31 below zero, RV antifreeze failed?

[Dodgemahal]

I see the forum format has changed since I have posted last.   I have a 2005 Bigfoot 9.6 truck camper.  The camper is covered and  is under a carport with an open front.  I winterize it every year with RV antifreeze.  I live in the Northern Idaho panhandle. This cold snap many people are seeing has hit me also. Last night it got down to -31 degrees below zero.  15 below is not unusual here. While making rounds to the shops and camper this morning I found that the 3 remaining unopened gallons of Camco RV and marine antifreeze rated to -50 below that I had on the shelf were frozen. At the time of finding this it was -9 below. I had intended to dump some down the toilet into the tank just in case. Looking in the camper the lines were also frozen.  The toilet valve was also stuck and frozen.  Naturally I got a little upset. I put a heater in the camper and it is still running now.  Has anyone seen this happen to their antifreeze in extreme cold weather?  I spoke to a friend about it, he talked with an acquaintance who winterizes dozens of boats in the Seattle area with the same stuff.  His friend said it can freeze but it is designed to not expand and break things. I looked and nothing looks broken. But I will know more later when temps rise.  From now on I am pushing the antifreeze out with 10 PSI of air to vacate the lines in my fall procedure.   I just wonder if anyone has any known experience with this problem or knows something I don't.  It still bothers me that it was supposed to be rated to -50.  Please see the picture of the new jug on it's side and nothing is fluid. It is solid. Thank you.

 

[MFL]

While some types of RV anti-freeze are better than others, most will turn to slush or freeze at extreme temps. It should not expand, cause any damage. I normally open low point drains, after using anti-freeze in Fall, and blow most out. It will be mostly pure, so I dump the small bucket of used AF down the toilet, to keep some liquid in black tank.

You should be fine come Spring, when you flush your system.

[Bedlam]

I also blow out lines and only use the anti freeze in the p-traps. I leave all faucets and drains open until ready to refill with water. This is a regular process for me in the winter since we go out twice month rain, shine, snow or ice.

[deserteagle56]

I must be doing something wrong...twice now I've tried just blowing out the water lines on my Bigfoot and using antifreeze only in the p-traps.  Both times there was enough water left somewhere in the system that it was frozen and I had to put heat in the camper until it thawed.  Condensation, maybe, as it was a few months before the camper was used?  So I've gone back to pumping the RV antifreeze through the lines and then flushing everything when I've ready use the camper.

[Dodgemahal]

I think trying to push water uphill or through the piping system with air pressure will cause air to bubble past the water in the pipe to a point while pushing it out. It will tend to move the water but remove the air pressure and the residual water will collect to a low point and freeze to form a plug.  Maybe a better method would be to empty the water, run antifreeze in to each faucet till you see pink fluid (including the outdoor shower unless you know for sure it is empty).  Then apply the air pressure to evacuate most of the antifreeze. Drain your waste tanks and fill your P traps. Do the soak and flush in the spring a few times to try and remove any traces of antifreeze smell. This will be my plan for next year. I really don't like that stuff in my pipes, but it beats broken stuff and very difficult to reach repairs.  The high quality water filter at my sink helps with toxic stuff staying out of your body. No point in working your filtering organs to the hilt.  I can also cook with that water knowing it is relatively clean.